Google has been testing cars that drive themselves, known as autonomous vehicles, and is now looking for a state that will allow them on the roads. Legislation to allow them has been introduced in Nevada and Google has hired a lobbyist to support the bill. According to a leader of the development team, the robotic vehicles would increase energy efficiency and improve safety. A New York Times article quotes the developer calling for “sophisticated systems for car sharing that, he says, could cut the number of cars in the United States in half. “What if I could take out my phone and say, ‘Zipcar, come here,’ ” he asked an industry conference last year, “and a moment later the Zipcar came around the corner?”